Handheld vacuum cleaners are popular with users due to their light weight and inherent portability, as well as the lack of power cords, which makes such vacuum cleaners particularly convenient for spot cleaning tasks as well as for cleaning larger areas. The cleaning efficiency of handheld vacuum cleaners is improving and it is known to equip a handheld vacuum cleaner with a cyclonic separating apparatus to separate the dirt and dust from the incoming flow of dirt laden air. One such example is disclosed in EP2040599B, which incorporates a first cyclonic separating stage in the form of a relatively large cylindrical cyclone chamber and a second cyclonic separating stage in the form of a plurality of smaller cyclones fluidly downstream from the first cyclonic separating stage. In such an arrangement, the first cyclonic separating stage works to separate relatively large debris from the airflow, whilst the second cyclonic separating stage filters relatively fine dirt and dust from the airflow by virtue of the increased separation efficiency of the smaller cyclones.
Whilst two-stage cyclonic separation is efficient at separating dirt and dust from the incoming airflow, it is still prudent to provide a filter downstream of the cyclonic separating apparatus and upstream of the motor in order to protect the motor from the ingress of fine dust which may still be entrained in the airflow. EP2040599B includes a generally planar filter member that is located in a recess adjacent an outlet duct of the cyclonic separating unit. The plane of the filter member lies generally parallel to the longitudinal axis of the cyclonic separating unit. Although this configuration permits a relatively large filter to be used, the overall size of the vacuum cleaner is increased significantly. It is with this drawback in mind that the invention has been devised.